GyraseA (GyrA) subunit of DNA gyrase from mycobacteria has certain characte
ristics distinct from that of E. coli. Polyclonal antibodies produced again
st M. tuberculosis GyrA recognized GyrA from different slow and fast growin
g mycobacterial species and also from several Gram-positive bacteria. Howev
er, these antibodies did not cross-react with E. coli GyrA and the enzyme f
rom other Gram-negative bacteria. The results from the present study togeth
er with multiple alignment, pairwise comparison and biochemical properties
support the idea of the occurrence of two subclasses of gyrases in the bact
erial kingdom, emphasizing the importance of the enzyme as a molecular targ
et for the development of novel therapeutics.